The effects of the vacuum sublimation process on the composition of C-60/C-70 films

Thermogravimetric (TG) analysis was carried out under atmospheric condition for C-60/C-70 powder mixture separated from soot by benzene Soxhlet extrac tion. The result indicates that the starting temperature for obvious sublim ation of C-60 is about 600 degrees C. The powder mixture was sublimated und er various technology conditions in high vacuum to prepare films on KBr cry stal substrates. Fourier transform IR (FTIR) spectra of the films, the powd er mixture and pure C-60 powder separated by chromatography reveal that the composition of films depends upon the experimental procedure and that pure C-60 film can be obtained under optimum process conditions. (C) 1999 Elsev ier Science S.A. All rights reserved.